The present invention relates generally to ink-receptive coating compositions and relates more particularly to a novel ink-receptive coating composition.
With the advent of computers, it has become easy to customize the layout of text, graphics and other information. A common device for printing such information from a computer is an ink-jet printer. Ink-jet printers typically utilize an aqueous-based ink in which colorants are delivered, together with a water-based vehicle, to an imaging substrate. The imaging substrate usually includes a carrier and an ink-receptive coating positioned over the carrier. To ensure good image quality, the ink-receptive coating should absorb rapidly the liquid component of the ink and at the same time immobilize the ink dye on the coating surface.
Various types of imaging substrates that are suitable for use with ink-jet printers currently exist. One such type of imaging substrate is referred to in the art as “an ink-jet recording sheet” and comprises an ink-receptive coating that is fixed relative to its carrier. Such ink-jet recording sheets are typically used to record printed information on the carrier in a durable fashion and may be used, for example, to generate printed documents or photographs. Alternatively, by applying an adhesive to the carrier of such a sheet opposite to its ink-receptive coating, such an ink-jet recording sheet may be used to make a customizable label. Another type of imaging substrate is referred to in the art as “a heat-transfer sheet” and comprises an ink-receptive coating that is removably secured to its carrier. In use, information is printed onto the ink-receptive coating of a heat-transfer sheet, and the ink-receptive coating is then transferred, typically under conditions of heat and pressure, from the carrier to a secondary substrate, such as a T-shirt.
In commonly-assigned U.S. Pat. No. 6,866,383, inventors Naik et al., which issued Mar. 15, 2005, and which is incorporated herein by reference, there is disclosed an ink-receptive coating composition that includes (a) a filler; (b) a binder having a Tg of less than 30° C.; and (c) a cationic polymer, wherein the composition, when coated on a substrate, forms an ink-receptive coating which accepts ink loading greater than about 300%. The coating compositions provide a printable surface receptive to high loading of ink-jet inks which do not crack at loading in excess of 300%, and in one embodiment, do not crack at loading up to about 400%. In addition, the print shows superior liquid resistance and the print quality of the inks is improved and a reduction in bleeding of colors occurs. Also, printed articles have outdoor durability especially those with overlaminates.
In commonly-assigned U.S. Pat. No. 6,780,924, inventors Shih et al., which issued Aug. 24, 2004, and which is incorporated herein by reference, there is disclosed an ink-receptive composition that contains a binder, a particulate filler, and a mordant. A preferred binder comprises one or more acrylic copolymers made with at least one wet abrasion resistance-enhancing monomer.
In commonly-assigned U.S. Pat. No. 6,623,841, inventors Venkatasanthanam et al., which issued Sep. 23, 2003, and which is incorporated herein by reference, there is disclosed an ink-receptive composition that is formed from a melt processable blend of a water-soluble polymer and a substantially water-insoluble polymer, and provides an inherently ink receptive surface without further surface treatment. The ink receptive blend comprises in the range of from 20 to 80 percent by weight water-soluble polymer, and in the range of from 20 to 80 percent by weight substantially water-insoluble polymer based on the total weight of the blend. The blend has a melting temperature in the range of from about 100 to 600° F. Preferred water-soluble polymers include polyvinyl alcohols and polyalkyl oxazolines.
In commonly-assigned U.S. Pat. No. 6,153,288, inventors Shih et al., which issued Nov. 28, 2000, and which is incorporated herein by reference, there is disclosed an ink-receptive composition that contains a pigment dispersed in a binder composed of an ethylene vinyl acetate emulsion polymer and at least one water soluble, cationic polymer, such as polydiallyldimethylammonium chloride and copolymers of a quaternary amino acrylate or methacrylate and a hydroxy-lower alkyl acrylate or methacrylate.